JPH0361124A - Control lever device for self-propelled working machine - Google Patents

Abstract

PURPOSE:To improve operability by pivoting a change lever and a neutral on a handle so that they can freely oscillate, and pulling or returning a wire engaging a hydraulic continuous variable gear by the neutral lever to control moving stroke of the wire by the change lever. CONSTITUTION:In a walking lawn mower loaded with a hydraulic continuous variable gear provided with a speed change cam plate tilted-moved by pulling and operating a wire 11, a dead man clutch lever 13 and a neutral lever 14 are pivoted on the same axis in close proximity to the grip part 12a of a handle, and a change lever 15 is provided to the handle 12, on the side of a machine body from the pivoted point. The one end of the wire 11 is supported on a guide pin 17c inserted into a vertical groove 16b of a change lever arm 16 provided rotatably relative to a circular-arc groove 15d of a disc part 15a of the change lever 15, and the disc part 15a. The change lever arm 16 is connected to the neutral lever 14 by a tension spring 21.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a control lever device for a self-propelled working machine.

(Prior art) Some self-propelled working machines, such as lawn mowers, snow blowers, and tillers, have a handle that extends rearward and upward from the machine body, and this handle is equipped with various operating levers. Showa 63-191
It is shown in the No. 121 publication.

(Problems to be Solved by the Invention) The handle of the lawn mower of the above-mentioned publication is provided with various levers, and for running, a gear lever for the running speed and a neutral lever that allows the wheels to rotate freely are used.

Each of these levers is connected to a hydraulic transmission by a wire,
These wires are stretched along the handlebar, but since there are multiple wires, attempts are made to unify these wires into a single wire, but while the swing stroke of the neutral lever is constant, the gear shift The above-mentioned implementation is difficult because the tilting angle of the lever needs to be changed depending on the desired speed.

In other words, there is a need for a technology that can unify the wires while making the functions of the neutral lever and the speed change lever effective using a simple mechanism.

(Means for Solving the Problems) In order to meet the above requirements, the present invention provides a shift lever and a neutral lever that are pivotably supported on the body or handle of a working machine.

The speed change lever is provided with a curved groove, the speed change lever arm is pivotally attached to the swing center of the speed change lever, the vertical groove of the speed change lever arm and the curved groove of the speed change lever are connected by a connecting member, and a The gear shift control operating member of the above-mentioned transmission device is engaged, and the gear shift lever arm is connected to the neutral lever.

The curved groove of the speed change lever is formed so that the radius from the center of swing gradually decreases, and the dog-shaped radius is disposed on the high speed side of the speed change lever.

(Function) The neutral lever swings and pulls/returns the speed change control operating member of the traveling transmission device, that is, the wire, to bring the work machine into a non-neutral/neutral state.

At this time, the wire connecting pin moves along the circular arc groove of the gear shift lever, and the movement stroke increases or decreases depending on the arc diameter, so that the gear shift lever adjusts its stroke according to its set position and performs the gear shifting action. Let's do it.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a side view of the lawn mower, and the walk-behind power lawn mower 1 is equipped with front wheels 3, 3 and rear wheels 4, 4 at the front and rear of a vehicle body 2. A blade 5 and an engine 6 are arranged. The output of the engine 6 is manually applied to a hydraulic continuously variable transmission 10 via a universal shaft 7, which changes and decelerates the speed and transmits the output to the 4.4 rear wheels.

The hydraulic continuously variable transmission 10 is an axial piston mechanism consisting of an oil pump 111, an oil motor 115, and a gear reduction mechanism as shown in FIG. Switching valve I20 (Showa 1i3-191121)
(See also Figure 9 of the publication). Specifically, the oil pump 111 includes a pump shaft 111a coupled to the universal shaft 7 extending from the output shaft of the engine 6;
A cylinder part IIB spline-fitted to this shaft, and a plurality of pistons 1llc slidably fitted to this cylinder part...
・A shift swash plate 112 that comes into contact with the tips of these pistons via a thrust bearing 111d, and a neutral switching valve 120 that can come into contact with this swash plate, and these are all housed in the pump case 111e. It will be done.

The shaft of the speed change swash plate 112 is supported at both ends by the pump case 1ife, and one of the shafts extends outside the case. An arm 10a is fitted to this shaft end 112a, and a wire 11 is attached to the tip of the arm 10a. One end of the wire is engaged, and the wire is rotated clockwise as shown in the drawing by pulling the wire.

Note that the arm 10a is always biased in the left rotation direction by a coiled return spring 112c.

Therefore, the hydraulic continuously variable transmission 10 increases the traveling speed by tilting the speed change swash plate by pulling the wire 11, and reduces or stops the traveling speed by loosening the wire II.

A handle 12 extends rearward and upward from the rear of the vehicle body 2 in FIG. 1, and various operating levers are provided on this handle.

FIG. 2 is a partially cutaway side view of the operating lever device, in which a clutch lever 13 and a neutral lever 14 are engaged with pins 13a and 13a on the handle 12 in the vicinity of the grip portion 12a of the handle. A gear shift lever 15 is provided on a handle 12 near the vehicle body.

FIG. 3 is an exploded perspective view of the speed change lever.
and a grip part 15b protruding from the upper end of these disc parts, a through hole 15c is formed in the disc part 15a, and an arcuate groove 15d is bored in the lower part of the disc part, and the disc part 15a,
A change lever arm 16 having a U-shaped cross section is housed between 15a.

The speed change lever arm 16 has a through hole 16a in the upper part, a curved longitudinal groove 16b in the middle part, and a small hole 16c in the lower part.

The shape of the curved longitudinal groove 16b of the shift lever arm 16 in FIG. 2 draws an arc R5 from the wire bending point P of the bracket 12b supporting the wire 11 when the neutral clutch lever 14 is off.

This is because no matter what position the gear shift lever 15 is set to, when the neutral clutch lever 14 is off, the swash plate of the hydraulic continuously variable transmission must return to the neutral position and the vehicle must be stopped. This is because the length of the wire must be constant when the neutral clutch lever 14 is off.

In addition, as shown in the figure, the circular arc grooves 15d of the disk portion 15a have circular arc diameters R1 to R4 centered on the through holes 15c.
It is formed so that ≧R2>R3>R4.

In addition, when the shift lever 15 is in the highest speed position, R1 is the radius when the neutral lever is off, and R2 is the radius when the neutral lever is on; in this case, R1
=R2. Further, when the shift lever 15 is at the lowest speed position, R3 is the radius when the neutral lever is off, and R4 is the radius when the neutral lever is on.

At high speeds, the neutral return force of the swash plate of the hydraulic continuously variable transmission that is interlocked with the gear shift lever increases, making it easier for the gear lever 15 to return. To solve this problem, a groove was provided as described below. When R1=R2, Ll of the curved groove of the gear shift lever 15
By forming the clutch into an arc shape, even if the neutral lever is switched from off to on, the shift lever 15 located at the highest speed side will not even return to the low speed side, and the clutch will be repeatedly turned on and off when driving at high speed. It is possible to maintain almost constant high-speed driving at a certain time.

After fitting the gear shift lever arm 16 between the disc parts 15a, 15a, connect them to the spindle 17a and the long nut 1.
7b and guide pin 17c to connect through the guide pin 17c.

FIG. 4 is a partial cross-sectional view of the gear shift lever, showing the spindle 17a and long nut 1 horizontally protruding inward from the handle 12.
Between 7b, there is a nine throttle lever 18 for adjusting the engine speed, a bracket 17d, and a spring seat 17.
e. The gear shift lever 15 and the gear shift lever arm 16 are interposed, and the bracket 17d is attached to a part (not shown) of the handle 12, and the throttle lever 18 is biased to this bracket by a spring 17f. 1
The set spring 17g on the opposite side of the spring 7d presses the serrated spring seat 17e against the disc portion 15a of the speed change lever. Notches on disk portion 15a and spring seat 17e
Since the gear shift lever 15 is engaged with the saw teeth of the shift lever 15, the shift lever 15 is appropriately fixed in position.

Furthermore, stoppers 17i and 17j are formed by bending and spaced apart from each other at both ends of the upper part of the bracket 17d (in the front and back directions in the drawing), and define the range of movement of the speed change lever 15.

Reference numeral 19 denotes a cover screwed to the bracket 17d, with scale plates 19a, 19a pasted on the top surface, and the gear shift lever 1
5 and the position of the throttle lever 18 are displayed.

FIG. 5 is a view in the direction of arrow A in FIG.
A dead man clutch lever 13 bent into an arch shape in substantially the same shape as 2a is disposed in front of the grip portion 12a (on the worker's side), and a neutral lever 14 is further disposed in front of the dead man clutch lever 13. Further, a switching lever 20 is provided on the left side of the dead man clutch lever 13 so as to be freely retractable.

Next, the connection relationship between the speed change lever 15, the neutral lever 18, and the wire 11 will be explained with reference to FIG.

Wire 11 extending from hydraulic continuously variable transmission 10 in FIG.
The wire guide 12b protruding from the handle 12 positions the wire in the radial direction, and extends further to engage the wire clip 11a at the tip with the guide bin 17c.

On the other hand, a small hole 16c at the bottom of the gear shift lever arm 16 is connected to a swing piece 14a at the bottom of the neutral lever 14 by a tension spring 21.

The levers mentioned above, especially the neutral lever 14
．． A control lever device 22 is constituted by the variable a lever 15 and the change lever arm 16.

The operation of this operating lever device will be described below.

The gear shift lever 15 tilts the gear shift plate of the hydraulic continuously variable transmission to change the traveling speed, and the neutral lever 14 puts the traveling system in a neutral state to enable manual movement of the vehicle. The deadman clutch lever 13 is used to disconnect the clutch 5a (see FIG. 1) located between the engine 6 and the lawn mowing blade 5.

6(a) to 6(c) are action explanatory diagrams, and FIG. 6(a)
), the operator moves the gear shift lever 15 in advance.
A case where the vehicle is tilted toward the high speed side until it hits the collar 17i will be explained.

Since the neutral lever 14 is released, the wire 1
1 is pulled by the return spring of the hydraulic continuously variable transmission 10, and the lawn mower 1 is in neutral.

Next, move the neutral lever 14 to
2a, and when the switching lever 20 is also grasped (FIG. 6(b)), the swinging piece 14a at the bottom of the neutral lever 14 is moved to the gear shift lever.
Bring the lower part of arm 16 closer together. As a result, the wire end 11a at the tip of the wire moves in the direction of the arrow (■) following the curved groove 15d, causing the arm 10a connected to the speed change swash plate to tilt (arrow (■)).

FIG. 6(C) shows a case where the operator has previously tilted the gear shift lever 15 to the low speed side and pulled the neutral lever 14 toward the handle grip portion 12a (arrow @) (hereinafter, this action will be referred to as on). , the wire end Ila is curved groove 1
5d, causing the arm 10a of the hydraulic continuously variable transmission to tilt (arrow ■).

Since the arc radius is set as R1, R2>...>R3>R4, Ll>L2, and thus the position of the speed change lever 15 and the traveling speed match well.

Furthermore, the fact that the neutral lever 14 can be turned on and off freely regardless of the position of the gear change lever 15 greatly improves operability.

If you want to mow the lawn without driving, you can turn off the neutral lever 14 and turn on the dead man clutch lever 13 while holding the switching lever 20; , the neutral lever 14 and the dead man clutch lever 1 without gripping the switching lever 20.
Just turn on 3.

Note that this operating lever device 22 is not limited to lawn mowers, but can also be used with snowplows,
It can be widely adopted in self-propelled working machines such as tillers.

(Effects of the Invention) As explained above, the present invention pivots the gear shift lever and the neutral lever on the handle so that they can swing freely, and allows the neutral lever to pull and return a piece of wire related to the hydraulic continuously variable transmission. In addition, the shift lever is configured to adjust the movement stroke of the wire, so that the shift operation and neutral operation can be switched and adjusted by a single wire operation, and the neutral lever and the shift lever can exert their respective functions. Therefore, the present invention simplifies the configuration of the operating lever of a self-propelled working machine and improves operability.

[Brief explanation of drawings]

Figure 1 is a side view of the lawn mower, Figure 2 is a partially cutaway side view of the operating lever device, Figure 3 is an exploded perspective view of the gear shift lever, Figure 4 is a partial sectional view of the gear lever, and Figure 5. 2 is a view taken along arrow A in FIG. 2, FIGS. 6(a) to 6(C) are action explanatory views, and FIG. 7 is a partially cutaway side view of the hydraulic continuously variable transmission. R1, R2, R3, R4...Radius 2...Vehicle body 10...Hydraulic continuously variable transmission 1
1... Wire 11a... Wire end 12.
・Handle 14 ・Neutral lever 15 ・
...Shift lever 15d...Curved groove 16...Shift lever arm 16b...Vertical groove 22...Operating lever device\GO-ku 1990/72

Claims (3)

[Claims] (1) A gear shift lever that defines the movement stroke of a wire related to speed adjustment of a transmission that changes the running speed of a self-propelled work machine is swingably supported on the body of the work machine, and the wire is pulled or An operating lever device for a self-propelled working machine, characterized in that a neutral lever, which turns off or engages a neutral mechanism provided in the transmission by returning the gear, is swingably supported on the body of the working machine. (2) The transmission is equipped with a transmission that changes the traveling speed, and this transmission is equipped with a neutral mechanism that freely frees the drive wheels, and the speed adjustment depends on the moving stroke of the wire, and the neutral mechanism is switched off and on. This self-propelled work machine has a handle that extends and a swingable neutral lever near the grip of the handle. A gear shift lever having a curved groove is swingably provided on the handle closer to the transmission device, a gear shift lever arm is pivotally attached to the pivoting center of the gear shift lever, a vertical groove is provided in the gear shift lever arm, and a vertical groove is provided on the gear shift lever arm. A self-propelled work machine characterized in that the curved grooves of the gear shift lever are connected by an interlocking member, the gear change control operating member of the above-mentioned transmission device is engaged with the interlocking member, and the gear shift lever arm is connected to a neutral lever. operating lever device. (3) The curved groove of the speed change lever is formed by gradually decreasing the radius from the center of swing of the speed change lever, and the larger radius is arranged on the high speed side of the speed change lever. The operating lever device for a self-propelled working machine according to claim 2.